Novel e8a2 BCR/ABL Fusion Transcript in Case of a Myeloproliferative Neoplasm

Abstract

Main objective of this work was to confirm the occurrence of rare BCR-ABL fusion variant involving the a2 region of the ABL gene and e8 of BCR gene in a patient of Myeloproliferative neoplasm positive for t(9;22) translocation but negative for common major and minor breakpoint cluster regions. A patient with elevated white blood cell count was subjected to classical cytogenetics, FISH as well as RT-PCR testing using commercial kits as well as published primers and in house testing protocol. The translocation event in chromosome 9 and 22 could be successfully detected. BCR/ABL dual color, dual fusion probe generated a classical balanced translocation scenario within the nucleus. In RT-PCR we found an unexpectedly large amplification band around 1700 bp, which is consistent with e8a2 transcript. Nine metaphases showed 46,XY,t(9;22)(q34;q11.2)[9] by cytogenetic. A rare e8a2 break point in the BCR-ABL gene in myeloproliferative neoplasm disease detected in India. It also emphasizes the utility of cytogenetic and FISH for primary diagnosis of any neoplasm in blood. Our Patient detected rare BCR-ABL fusion variant e8a2 was on imatinib 400 mg since last 3 months. After 3 months fluorescent in situ analysis and reverse transcriptase pcr analysis showed negative results.

Keywords: BCR-ABL; FISH; MPN.

Fig. 1

In left side 7th lane of gel picture shows e8a2 transcript (~1700 bp) and in right side BCR-ABL fusion signal by FISH indicated by arrow